class Account:
    def __init__(self):
        self.keys = []
        self.values = []
        self.transactions = []
    def __str__(self):
        return str(self.keys) + str(self.values) + str(self.transactions)

class Transaction:
    def __init__(self):
        self.keys = []
        self.values = []
    def __str__(self):
        return str(self.keys) + str(self.values)
                
class Message:
    def __init__(self):
        self.msg = ''
        self.date = ''
        self.accounts = []
    def __str__(self):
        return str(self.msg) + str(self.date) + str(self.accounts)
